Drill.



J. T. HOAL.

DRILL.

APPLICATION FILED FEBJ?, 1013.

Patented Aug. 4, 1914.

2 SHEETS-SHEET 1.

J. T. HOAL.

DRILL.

2 SHBETBSHEET 2.

UNITED STATES PATENT oEEIoE.

JAMES T. HOAI, OF ATLANTA, GEORGIA.

muti..

To all whom it may concern.'

Be it known that I, JAMES T. HoAn, a citizen of the United States, residin at Atlanta,*in the county of Fulton and tate of Georgia, have invented certain new and useful Improvements in Drills; and Ido hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others .skilled in the art to which it appertains to make and use the Same.

This invention comprehends improvements in rock or concrete drills and relates more particularly to those of the type which employ a reciprocating hammer actuated by any suitable power.

The primary object of the invention resides in the provision of a drill of this type, which shall be of extremely simple construction, which will be very strong and durable, and which will be especially adapted for drilling holes in concrete and similar substances.

Another important object of the invention is to provide a drill of the character described which employs a reciprocal hammer that is provided with novel means whereby desired regulation of its reciprocal movement may be had, said regulating means being held in adjusted position by novel means forming a part of the invention.

With these and other objects in view, as will become more apparent as the description proceeds, the invention consists in .certain novel features of construction, comblnation, and arrangement of parts as will be hereinafter described and claimed.

For a complete understanding of my 1n vention, reference is to be had to the follow ing description and accompanying drawings in which,

Figure 1 is a side elevation of my im proved drill, the face plate thereof being rc.- moved and the drill shown partly in section, Fig. 2 is a longitudinal sectional view,Fig.

3 is an enlarged end elevation, partly in sec-Y l tion, showing the hammer in its raised position, Fig. 4 is an .enlarged transverse sectional vlew taken on the plane of line 4-4 of Fig. 2, and, Fig. 5 is a fragmentary side elevation, showing the pivot adjusting and locking means.'

Infthe following description and accompanyi-ng drawings, similar parts will be re- Specification of Letters Patent.

Application filed February 17, 1913.

Patented Aug. 4, 1914.-.

serial No. 748,951.

ferred to and designated by like reference characters.

Referring in detail to the drawin A designates, generally, the body of my improved drill and is in the form of an elongated shell or housing, and comprises the member 1 and removable face plate 2. -The up er end of the body or casing is formedwlt an internally threaded socket 3 into which one end of a tube 4 is threaded'. A handle 5 is secured to the other end of the tube by means of a set screw 6. The casing is enlarged adjacent its socketed end to form the annular chamber 7 in which a wheel or disk s is aapted to revolve. 'The disk 8 is threaded upon a shaft 9 which extends outwardly through a bearing 19 formed integralwith the body A. For the purpose of illustration, I have shown a crank handle 1l secured upon the outer end of the shaft 9, whereby the shaft may be Irotated, but it is to be understood that any other suitable means may be employed for furnishing power to said shaft. A plurality of pins 12 are threaded into one face of the disk 8, projecting'laterally therefrom, and carry the yrollers 13. The pins are arranged at equal distances from each other and in a circle concentric with the shaft 9.

An eccentric pin 14 having a head 15, extends through the member 1, is squared as indicated at 16, and has its extremity reduced and threaded, as indicated at 17, to

. receive the nut 18. The head 15 of the pin engages the inner face of the member 1 and has a lug 19 formed eccentrically upon its other face. A bell-crank 2O is pivotally mounted intermediate its ends upon the lug 19 and is adapted to have its free arm 21 engaged by the rollers 13. To adjust the pivot point of the bell-crank, I provide a spring steel arm 22, which is fitted over the squared portion 16 of the eccentric pin. The free end of this arm is adapted to seat between any two of the lugs 23 which are arcuately formed upon the body A..

A hammer 24 is slidably mounted within the casing or body A and is formed with a head 25 upon one end. The movement of the hammer in one direction is limited by the reduced portion 26 of the body. The head moves within a cylindrical chamber 27 and an expansive spiral spring 28 surrounds the g hammer, bearing against the head 25 and onic end of the chamber 27. The hammer is bifurcated at its inner end, as indicated at 29,

to receive one arm ont the bell-crank 20. 'lhe bell-crank is slotted, as indicated at 29, to receive the pin 30, which has its ends tired into 5 the hammer.

A drill chuck 3l having a iiange 32 torined thereon, is slidable Within one end oi the body A. The chuck is adapted to hold a drill 33, Which may be of any preferred con- 'w struction. rThe ange 32 is'slotted, asmindi cated at 34, to receive a pin 35, 'which pin prevents rotation of the chuck relative to the bodyD A sleeve 38 is threaded into the end of the body and serves to retain the chuclr in 15 the prop-er position. The flange 32 is slidable Within a chamber 3'?, one end Wall oi which is formed by the sleeve 36 ln operation, the machine is supported in any desired manner with the drill 33 agains 2.@ the substance to be Worked. disk 8 is rotated so as to bring the rollers il?. rapidly `into engagement with the' free arm oit the bell-crank 20.. Each roller forces the hellcranlr from its path, which causes an inward movement oit the lmrnmer whereloy the spiral spring is contracted., When the roller asses out or enano-'ement with the p c: c

loell-cranlr7 the spring drives the hammer sharply against the drill chuck. 'lhis last movement returns the tree end oi the hell cranlr to the path the rollers the op eration is repeated, ihe strolre ci the hamn mer may he regulated by adjustment of the eccentric pin and this can he easily acas complished by shitting the `to a new position, said arm being preferably formed ont spring steel to permit it to he moved over the lugs 28. 'ifo increase the length oi? the strolre, the spring arm 22 is moved in a dia@ rection which `will move the "aree of the 'hell-crank farther into the path or travel oit the rollers 13 Wherehy agreater hearing surface therefor is afforded by theA arm 2l and the adjusted position or the ern a@ 2l.' is maintained joy allowing the l spri. e"

armto rit between the lugs 2d formed on the' casing, "lit" will thus be seen that the length oil the' strolre of' the hammer may be regulated to desired degree by :so above described means. This means of adjustment l consider to be one or the mary features of my invention7 From the foregoing escription talren in connection with the accompanying draras ings, it will he seen that l have designed a drill in which the hammer may he very idly `reciprocated with the use ofthe 'mini'- mum amount or power. t is to be under stood that While l have Ashown and dean scribed the preferred embodiment of my inM vention, l do not wish to be limited to this exact constructiom combinatiom and arrangement of parts, but may maire such changes as Will fall Within the spirit and es scope or the invention;s

lla-ving thus described my intentiona what l claim is l. ln a drill oi the character described, the combination of a casing, a rotatable memberr journaled therein, a bell-crank, means carried by said rotatable member for rocking said bell-crank, an eccentric pin forminga pivotal support for the bell-crank, an arm iizred to said pin to turn the same, means for locking the arm in any desired position, comprising a plurality of arcuately arranged spaced lugs formed upon said casing, a hammer pivotally secured to and ac tuated by said -bell-cranlr, spring means 1 most positiona said pin being squared for a portion of its length7 an arm fitted upon said sqinired portion7 means :for holding1 said arm thereon, a plurality oi lugs arcuatel arranged upon said casing, said arrnheing adapted :to tit between certain of said lugs whereby an adjustment oi the length of the stroke ot said hammer is facilitated.

3. lin a device ot the character described the combination with a casing, of a hammer reciprocatingly mounted therein, means for reciprocating said hammer mounted 'Within sai casing comprisingl a spring mounted upon said hammer'9 abell-crank pivoted upon the' 'upper terminal or said hammer, an annular dish rotatably mounted Within said casing, a plurality of pins mounted in spaced relation upon said disk and adapted ior engagement with the bell-crank, and an erteriorly operable crank handle secured to seid dish land means :for regulating the reciprocal action of said hammer compris ing a spring arm operatively connected with the hell-crank and means for locking said last named means in adjusted position formed integrally with the casina upon the outer side thereof and adapted tor engagement with said arm a. ln a device of character described the combination with a casing' ori a hammer reciprocatingly mounted therein, means for reciprocating said hammer including a spring, a rotatable member journaled Within said casing, a plurality of spaced pins mounted upon said rotatable memberyfa hell-cranky operatively connected with the hammer and a cranlr handle operatively lil@ connected with the rotatable member, and means for regulating the reciprocal movement of said hammer comprising a pin rotatably mounted in said casing, an eccentric lug formed on the inner end of said pin and operatively connected withl the bell-crank, a spring arm secured to the outer end of said pin, means for securing said sprin arm to said pin and means for locking sai spring arm in adjusted position comprising 10 a plurality of integrally formed and arcuately arranged 1u s earned by said casing.

In testimon W ereof I affix my signature in presence o two Witnesses.

JAMES T. HOAL. Witnesses:

EDWARD L. ScovELL, WILLIAM M. SMITH. 

